src/newgrf_class.h

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   4  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file newgrf_class.h Header file for classes to be used by e.g. NewGRF stations and airports */
   9
  10 #ifndef NEWGRF_CLASS_H
  11 #define NEWGRF_CLASS_H
  12
  13 #include "strings_type.h"
  14
  15 /* Base for each type of NewGRF spec to be used with NewGRFClass. */
  16 template <typename Tindex>
  17 struct NewGRFSpecBase {
  18         Tindex class_index; ///< Class index of this spec, invalid until class is allocated.
  19         uint16_t index; ///< Index within class of this spec, invalid until inserted into class.
  20 };
  21
  22 /**
  23  * Struct containing information relating to NewGRF classes for stations and airports.
  24  */
  25 template <typename Tspec, typename Tindex, Tindex Tmax>
  26 class NewGRFClass {
  27 private:
  28         /* Tspec must be of NewGRFSpecBase<Tindex>. */
  29         static_assert(std::is_base_of_v<NewGRFSpecBase<Tindex>, Tspec>);
  30
  31         uint ui_count = 0; ///< Number of specs in this class potentially available to the user.
  32         Tindex index = static_cast<Tindex>(0); ///< Index of class within the list of classes.
  33         std::vector<Tspec *> spec; ///< List of specifications.
  34
  35         /**
  36          * The actual classes.
  37          * @note This may be reallocated during initialization so pointers may be invalidated.
  38          */
  39         static inline std::vector<NewGRFClass<Tspec, Tindex, Tmax>> classes;
  40
  41         /** Initialise the defaults. */
  42         static void InsertDefaults();
  43
  44 public:
  45         using spec_type = Tspec;
  46         using index_type = Tindex;
  47
  48         uint32_t global_id; ///< Global ID for class, e.g. 'DFLT', 'WAYP', etc.
  49         StringID name;    ///< Name of this class.
  50
  51         /* Public constructor as emplace_back needs access. */
  52         NewGRFClass(uint32_t global_id, StringID name) : global_id(global_id), name(name) { }
  53
  54         /**
  55          * Get read-only span of specs of this class.
  56          * @return Read-only span of specs.
  57          */
  58         std::span<Tspec * const> Specs() const { return this->spec; }
  59
  60         /**
  61          * Get read-only span of all classes of this type.
  62          * @return Read-only span of classes.
  63          */
  64         static std::span<NewGRFClass<Tspec, Tindex, Tmax> const> Classes() { return NewGRFClass::classes; }
  65
  66         void Insert(Tspec *spec);
  67
  68         Tindex Index() const { return this->index; }
  69         /** Get the number of allocated specs within the class. */
  70         uint GetSpecCount() const { return static_cast<uint>(this->spec.size()); }
  71         /** Get the number of potentially user-available specs within the class. */
  72         uint GetUISpecCount() const { return this->ui_count; }
  73
  74         const Tspec *GetSpec(uint index) const;
  75
  76         /** Check whether the spec will be available to the user at some point in time. */
  77         bool IsUIAvailable(uint index) const;
  78
  79         static void Reset();
  80         static Tindex Allocate(uint32_t global_id);
  81         static void Assign(Tspec *spec);
  82         static uint GetClassCount();
  83         static uint GetUIClassCount();
  84         static NewGRFClass *Get(Tindex class_index);
  85
  86         static const Tspec *GetByGrf(uint32_t grfid, uint16_t local_id);
  87 };
  88
  89 #endif /* NEWGRF_CLASS_H */